Fix flaky test

[cstenglein]

See https://github.com/raspiblitz/raspiblitz-web/actions/runs/13336974116/job/37254245696?pr=822

 FAIL  src/pages/Home/SendModal/__tests__/ConfirmSend.test.tsx > ConfirmSend > on chain tx with amount above zero > valid form passes
Error: expect(element).not.toBeDisabled()

Received element is disabled:
  <button
  class="z-0 group relative inline-flex items-center justify-center box-border appearance-none select-none whitespace-nowrap subpixel-antialiased overflow-hidden tap-highlight-transparent data-[pressed=true]:scale-[0.97] outline-none data-[focus-visible=true]:z-10 data-[focus-visible=true]:outline-2 data-[focus-visible=true]:outline-focus data-[focus-visible=true]:outline-offset-2 min-w-20 h-10 text-small gap-2 rounded-full opacity-disabled pointer-events-none [&>svg]:max-w-[theme(spacing.8)] transition-transform-colors-opacity motion-reduce:transition-none bg-primary text-primary-foreground data-[hover=true]:opacity-hover px-8 py-6 font-semibold"
  data-disabled="true"
  disabled=""
  type="submit"
/>
 ❯ src/pages/Home/SendModal/__tests__/ConfirmSend.test.tsx:244:13
    242|           name: "settings.confirm",
    243|         }),
    244|       ).not.toBeDisabled();
       |             ^
    245|     });
    246|   });

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 Test Files  1 failed | 15 passed (16)
      Tests  1 failed | 63 passed (64)